1. Field of the Art
The present invention relates to a process of creating simulated agglutinates. Agglutinates are individual particles that are aggregates of smaller lunar soil particles (mineral grains, glasses, and even older agglutinates) bonded together by vesicular, flow-banded glass. The simulated agglutinates can have many of the properties that are unique to real agglutinates found in the lunar soil, including: (1) a highly irregular shape, (2) heterogeneous composition (due to the presence of individual soil particles), (3) presence of trapped bubbles of solar wind gases (primarily hydrogen) that are released when the agglutinates are crushed, and (4) the presence of very small iron metal droplets or globules (including “nanophase” iron) that often exists in trails or trains on and within the agglutinitic glass.
2. Description of Prior Art
Dr. Paul Weiblen (University of Minnesota) attempted to create simulated agglutinate particles by dropping Minnesota Lunar Simulant (MLS) through a 6000 C plasma torch within an in-flight sustained shockwave plasma reactor. This was a viable method for producing simulants of some glassy components of the lunar soil, but it failed to produce accurate analogs of lunar agglutinates. (Weiblen, Paul, Marian Murawa, and Kenneth Reid. 1990. “Preparation of Simulants for Lunar Surface Materials,” Engineering, Construction and Operations in Space II, ASCE Space 1990, pp. 98-106.) Researchers at the University of Indiana have reported the formation of iron globules (200 nm to 1 mm in diameter) in a glass matrix that was heated to 1277 C in a hydrogen gas atmosphere for 20 hours. (Buono, Antonio, James Brophy, Juergen Schieber, Abhijit Basu. 2005 “Experimental Production of Pure Iron Globules from Melts of Lunar Soil-Compositions,” in Lunar and Planetary Science XXXVI, Abstract No. 2066, Lunar and Planetary Institute.) Researchers at the University of Tennessee have reported a similar method to create an agglutinitic glass simulant that contains “nanophase” iron particles (defined as metallic iron particles with a diameter of less than 50 nanometers). (Lui, Yang, Larry Taylor, James Thompson, Eddy Hill, and James Day. 2005. “Simulation of Nanophase Fe0 in Lunar Soil for Use in ISRU Studies,” in Meteoritical & Planetary Science, 40 suppl. A 94.) (Y. Liu, L. A. Taylor, J. R. Thompson, A. Patchen, E. Hill, J. Park. 2005. “Lunar Agglutinitic Glass Simulants with Nanophase Iron,” Abstract #2077 and Poster Presentation at Space Resources Roundtable VII: LEAG Conference, Lunar & Planetary Institute, LPI Contribution No. 1318.) Other researchers at the Laurentian University have reported the use of a vapor deposition technique to create nanophase iron surface deposits. (Mercier, Louis, Luc Beaudet, and Roger Pitre. 2006. “Formation of Nanophase Iron Inside Mesoporous Silica Frameworks: Novel Preparation Strategies for Optimized Synthetic Lunar Regolith Formulations,” Technical Paper 5-5 at the Planetary & Terrestrial Mining Sciences Symposium, Sudbury, Ontario.) All of these researchers succeeded in creating simulated agglutinitic glass with some degree of fidelity, but none of them created simulated agglutinate particles that have the same size, highly irregular shape, heterogeneous composition, and vesicular glass exhibited in lunar agglutinates.